Starting today, you can now add up to two tags to a Hubski post. There are a number of reasons behind this decision, but these are the two primary ones:
1) Many users have asked for more flexibility when tagging an article. For example, if you post an article about Mars, is it better to tag it #space or #mars? The decision whether or not to choose a general or specific tag can be frustrating. Now you can do both.
2) This will improve our signals for content discovery. Allowing a post's author to be more specific about the content will allow us to better understand what the post is about. In turn, we will be able to better identify relavent posts for content discovery mechanisms that we are currently working on.
Functionally, a second tag works just as the first. You can follow them, and you can ignore them.
Of course, I'd be happy to further discuss the rationale behind the second tag below.
As always, feedback is much appreciated!